To eat there, you have to be an employee or guest of Regeneron Pharmaceuticals Inc.

This week, the employee cafeteria at Regeneron's East Greenbush campus officially reopened under the management of Mazzone Hospitality. There are 600 Regeneron employees (and counting) working around-the-clock at the site.

Regeneron (Nasdaq: REGN) competitively bid the contract. With it, the Mazzone Hospitality brand now has operations in at least seven cities or towns in the Capital Region.

Regeneron employees have no photos of their old cafeteria, but they share this anecdote to describe the dramatic transformation: After-hours, a group of workers used to do pilates workouts in the old cafeteria.

Pitas, not pilates, are more suitable for the new cafeteria, which I saw June 26 on a tour of Regeneron.

"It's like an upscale Panera," said Dan Van Plew, modern lighting suspended above his head. Van Plew is senior vice president and general manager at the Regeneron campus.

Mazzone has been steadily expanding his corporate work. His company already runs the cafeterias at the Golub Corp. headquarters in Schenectady (parent of the Price Chopper grocery store chain), as well as Ayco Co., the largest financial adviser in the Capital Region.

Mazzone also has the contract to feed the 2,100 employees at the GlobalFoundries Inc. computer-chip manufacturing campus in Malta—and also the construction workers still on site (an average of 1,500 or more per day).

The idea to overhaul the cafeteria came out of employee meetings late last year. The cafeteria would have opened earlier, Van Plew said, if not for needing to prioritize an ongoing, $70 million expansion of office, lab and production space.

"Our people spent at least as much time here as they do with their families. So in my book, we should at least do two things: One, they should be safer here than anywhere else, and two, they should be able to get a darn good meal," Van Plew said.

The cafeteria is now called "Prime at IOPS." Mazzone uses the word "prime" throughout his brand, while IOPS is a Regeneron acronym for their East Greenbush site (industrial operations and product supply).